Radio telgraphy and telephony receiver.



G. W.,PICKARD.'

RADIO TELEGRAPHY AND TELEPHONY RECEIVEIM APPLICATION FILED OCT. 12. 19!.5.

1 45,267 Patented Nov. 6, 1917.

Attest: In Ve tor:

M W y Q/QAMAI WW 0 W m/ M.. Attyv v UNITED STATES PATENT OFFICE.

GREENLEAF WHITTIER PICKARD, OF AMESBITRY, MASSAOHUSETTS, ASSIGNOR TO WIRELESS SPECIALTY APPARATUS COMPANY, OF BOSTON, MASSACHUSETTS, A COB.-v

PORATION OF NEW YORK.

Original application filed March 28, 1914, Serial No. 827,845.

Specification of Letters Patent.

Patent No. 1,184,376, dated May 23, 1916.

Divided and this application filed October 1 2, 1915. Serial No. 55,370.

To all whom it may concern:

Be it known that I, GREENLEAF WHITTIER PICKARD, a citizen of the United States of America, and a resident of the town of Amesbury, Massachusetts, have invented certain new and useful Improvements in Radio Telegraphy and Telephony Receivers, the principles of which are set forth in the following specification and accompanying drawings, which disclose the form of the invention which I now consider to be the best of the various forms in which the principles of the invention may be embodied.

This invention relates to improvements in receiving apparatus for radio telegraphy and telephony, and consists of the apparatus and arrangements thereof disclosed herein, the object of the invention being to provide simplified and more eflicient apparatus.

In the drawings, the figure is a diagrammatic illustration of one embodiment of the invention. I

The receiving coil P is preferably a long coil, so that there will be a long overhanging portion, as at the left of the adjustable connection with antenna A. The other end of this over-hanging portion is connected to one terminal of the detector D, around which is connected telephone T. The other terminal of detector D is connected to along coil S which does not necessarily have any coupling with respect. to primary coil P.

While it is not necessary to varythe inductance of coil S, it may sometimes be found advantageous to wind this permanently for resonance with a desired wave length.

I In use, the operator adjusts the arrow connection from antenna A, and makes any desirable usual detector D adjustments, until 1 e obtains the best results from any given transmission, as indicated by telephone T.

The detector D is preferably of a type having high resistance and best operated by a current of high potential, and connected as it is to one end 0 coil P, it is subjected to the large potential changes thereat. The detector may be any of the so-called crystal rectifiers, particularly those of high resistance, such as my silicon detector; or it may be any other suitable detector.

This application is a division of my application Serial Number 827,845 filed March 28, 1914, granted as Patent Number 1,184,376, May 23, 1916.

In a radio receiving system, the combination with a receiving coil acting as a transformer, of an open circuited coil connected therewith by way of a detector, substantially as and for the purpose described.

GREENLEAF WHITTIER PICKARD.

Witnesses:

W. R. WARNER, LOUISE M. BRUNS..

Patented Nov. 6, 1917. 

